Submission #239317

#	Time	Username	Problem	Language	Result	Execution time	Memory
239317		dsjong	Political Development (BOI17_politicaldevelopment)	C++14	100 / 100	2850 ms	66200 KiB

politicaldevelopment

#include <bits/stdc++.h>
using namespace std;
int sz[100005];
bool good[2000];
vector<int>adj[100005];
map<pair<int, int>, int> mp;
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int n, k;
    cin>>n>>k;
    for(int i=0;i<n;i++){
        int d;
        cin>>d;
        for(int j=0;j<d;j++){
            int x;
            cin>>x;
            adj[i].push_back(x);
            mp[{i, x}]=true;
        }
        sz[i]=d;
    }
    int ans=1;
    for(int t=0;t<n;t++){
        int mini=INT_MAX, idx;
        for(int i=0;i<n;i++){
            if(sz[i]<mini){
                mini=sz[i];
                idx=i;
            }
        }
       // cout<<idx<<endl;
        vector<int>v;
        for(int i:adj[idx]){
            if(sz[i]<=n) v.push_back(i);
        }
        int m=v.size();
        good[0]=true;
        for(int i=1;i<(1<<m);i++){
            int lg=log2(i);
            int x=i-(1<<lg);
            if(good[x]){
                bool b=true;
                for(int j=0;j<m;j++){
                    if((1<<j)&x)
                        if(j!=lg) b&=mp[{v[j], v[lg]}];
                }
                good[i]=b;
            }
            else good[i]=false;
            if(good[i]){
                int cnt=0;
                for(int j=0;j<m;j++){
                    if((1<<j)&i) cnt++;
                }
                ans=max(ans, cnt+1);
            }
        }
        sz[idx]=INT_MAX;
        for(int i:adj[idx]) sz[i]--;
    }
    cout<<ans;
}

Compilation message (stderr)

politicaldevelopment.cpp: In function 'int main()':
politicaldevelopment.cpp:60:16: warning: 'idx' may be used uninitialized in this function [-Wmaybe-uninitialized]
         sz[idx]=INT_MAX;
                ^

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 38 / 38
• Subtask 5: 23 / 23